An antimicrobial coating system and method are described. In some embodiments, a system may include a composition. The composition may include one or more bridged polycyclic compounds. At least one of the bridged polycyclic compounds may include at least two cyclic groups, and at least two of the cyclic groups may include quaternary ammonium moieties. In some embodiments, a method may include applying an antimicrobial coating to an oral surface, a surface of a construction substrate, a surface of a marine substrate, a surface of a medical device, or a surface of a personal care device. The protective coating may be antimicrobial. A protective coating may include antimicrobial bridged polycyclic compounds. Bridged polycyclic compounds may include quaternary ammonium compounds. Bridged polycyclic compounds based coating systems may impart self-cleaning properties to a surface (e.g., a tooth surface).
